I will protect your pensions. Nothing about your pension is going to change when I am governor. - Chris Christie, "An Open Letter to the Teachers of NJ" October, 2009

Friday, December 16, 2011

Poverty, Shmoverty! Part II

As I said before, Amanda Ripley misstated Diane Ravitch's claims about international comparisons of poverty; she doesn't seem to understand a low-poverty district still has poor kids, so it and others like it can be compared to a low-poverty country, which also has poor kids.

The free/reduced-price lunch figure measures the number of kids from families making 185% of federal poverty line, right? So that means a family of 4 needs to make less than about $40,000 to qualify. Under this measure, roughly 40% of American kids qualify as “poor.”

OK. Then the other measure is the measure usually used in international comparisons of poverty. That is the percentage of kids from families earning less than 50% of the median income in that country. (In the US, this comes out to about 22%. NOT 40%.)

[...]

Conversely, PISA’s own measure of socio-economic background, the one you can find detailed in Table II.3.1 in PISA Volume II, offers a more valid comparison. And yet Ravitch does not cite it—because it does not show what she wants it to show.

I have been to Finland, Korea and Poland working on this book, and I have the luxury of spending hours reading PISA results. Most writers do not. They just repeat what Ravitch and others say. And so the magical thinking continues.

As Figure II.3.2 shows, the gradient line for many countries is roughly linear. Although the OECD average in the index of curvilinearity is -1 and statistically significant, it can be considered as practically linear. In some countries, however, the gradients are steep at low levels of economic, social and cultural status, and tend to level off at higher status levels, signalling that there is progressively less associated advantage in student performance at higher levels of socio-economic background. This phenomenon is moderate in the Slovak Republic, Norway, Japan, Iceland and Hungary, and is also visible in Finland, Ireland, Poland, Italy, Denmark and Sweden and in the partner economy Hong Kong-China. However, in another group of countries, most notably in the United States and the Netherlands but also in Chile and Canada and the partner countries and economies Panama, Kyrgyzstan, Trinidad and Tobago, Brazil, Argentina, Thailand, Colombia, Indonesia and Tunisia, the gradients are relatively gentle at low levels of socio-economic background, becoming steeper at higher levels (Table II.3.2). In these countries, the greater the socio-economic advantage, the greater the marginal increase observed in student performance, and among students from socio-economically less advantaged backgrounds, there are small differences in performance. [emphasis mine]

In other words: in the USA - more than any other country in the OECD - way more wealth means way larger increases in learning.

Now, I've read Diane Ravitch. I've heard her speak on several occasions. She even answers my tweets now and then. And I am here to tell you, this is exactly what she is talking about. Socio-economic status matters; in the US, it matters a lot. Are you seriously going to try to tell me that it's the poor quality of more-affluent American schools that's responsible?

Because Ripley says "rich kids" in the US do poorly compared to "rich kids" in other countries:

The most respected international tests of teenagers around the world (PISA) has consistently shown that our most-affluent kids do not perform as well as the most-affluent kids in the highest-performing countries around the world (even though our rich kids are richer than their rich kids). PISA measures students’ economic, social and cultural status to get a sense of their socio-economic background. In reading, American kids’ best subject, our most affluent students still rank behind the most affluent kids in six other countries. (Even though we spend far more money per student than all of those countries.)

OK, back to that beloved PISA report; Ripley took the above from p.165. You know how the report defines "rich kids"? Top 10%? Top %5? 1%?

Nope: top 25%. You think maybe there's a little variation in that group?

Remember: that same report says that in the US, your test scores go higher faster the wealthier you are. So it's quite conceivable our top 10% most-affluent kids - or 5%, or 1% - are killing it on these tests. Do we know? Of course not. But that doesn't stop Ripley from believing - or not.

Look, I could do this all night, but here's the takeaway: there is an indisputable correlation between poverty and student achievement. You can try to bad-mouth our schools all day long, but that's the fact. We have huge income inequity in this country, and it's affecting our kids. It's ridiculous to expect the schools to mitigate all of this.

One last thing message for Ripley: argument by authority is really, really boring. I don't care if you've been to the North Pole; Ravitch has a valid point in her comparison, and your floundering around trying to play "gotcha" is not going to be validated by your passport.